JP2567442Y2 - Drive device for bucket with breaker - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a bucket with a breaker which automatically controls a breaker provided on the bucket in accordance with digging resistance.

[0002]

2. Description of the Related Art A hydraulic excavator 1 shown in FIG. 5 is used for excavating a ground or a pavement at a construction work site or the like. A bucket 6 is assembled via an arm 5 to the tip of a boom 4 that swings from the upper swing body 3. The boom 4 swings up and down by driving a hydraulic boom cylinder 4a, and the arm 5 pin-coupled to the tip of the boom 4 also swings up and down by driving the hydraulic arm cylinder 5a. The bucket 6 is connected to the arm 5 by the connecting pin 7.
The tip of a rod 8 rotatably attached to the tip and extending from a bucket cylinder 6 a with the head side connected to the arm 5 is connected to the bucket 6 by a connecting pin 9. As a result, the bucket 6 swings back and forth according to the expansion and contraction of the rod 8, and excavates the ground with the cutting edge at the tip.

[0003] The above-mentioned hydraulic excavator 1 has no problem when performing ordinary ground excavation. However, when excavating hard ground such as earthen rocks, soft rocks or gravels, or when ripping paved roads. For example, because the ground was hard, the normal excavation force was transmitted to the bucket 6 as it was,
I can't dig the way I want. Therefore, when excavating the ground exceeding the normal excavation resistance, the bucket 6 at the tip of the arm 5 is replaced with a hydraulic breaker (not shown) suitable for crushing hard ground, and the excavation is performed by the impact or vibration generated by the hydraulic breaker. Methods are being taken to increase efficiency.

[0004] However, although the hydraulic breaker is suitable for crushing hard ground, it is completely unsuitable for loading work of shaved rocks and earth and sand into a transport vehicle or the like. The breaker must be replaced with the original bucket 6. In addition, when the soil quality is rich in hard and soft changes, the hydraulic breaker and the bucket 6 must be frequently replaced each time the soil quality changes, and it takes time to replace the excavator at the tip of the arm 5. Therefore, the efficiency of the excavation work was inevitably reduced.

On the other hand, in order to cope with such a problem, there has been proposed a hydraulic shovel of a type in which a hydraulic breaker is assembled to a bucket and integrated, and the hydraulic breaker is operated as required. In this case, the hydraulic breaker is covered by a protective plate on the bottom plate of the bucket, operates in response to a button operation by an operator, and vibrates to drive a tooth or a tooth, that is, an excavating tooth, which projects forward from the cutting edge of the bucket. As a result, the impact is continuously and repeatedly applied to the ground. This hydraulic breaker can be operated only when excavating ground with high excavation resistance, and it does not hinder the loading work of crushed earth and sand, etc. Another advantage is that the efficiency of excavation work is greatly improved.

[0006]

A hydraulic excavator in which the above-described hydraulic breaker is assembled to a bucket and integrated therewith has much higher workability than a conventional hydraulic excavator in which the hydraulic breaker and the bucket are separate bodies. However, the decision whether or not to activate the hydraulic breaker is left to the operator's own judgment, and therefore, when it is clear that the excavation resistance is larger than usual, such as in ripping work on paved roads It is good, but when digging a place where hard and soft ground is intricately complicated in a narrow area, it may be difficult to judge when to activate the hydraulic breaker. It was difficult to switch the breaker excavation timely.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a breaker-equipped bucket drive device in which a breaker integrated with a bucket is automatically operated only when the excavation resistance exceeds a threshold value.

[0008]

A driving device for a bucket with a breaker according to the present invention comprises a breaker for driving a digging tooth by fluid pressure, a bucket provided with the breaker, and a digging resistance exceeding a predetermined value. And a breaker control means for operating the breaker.

The breaker control means determines a threshold value of the excavation resistance from a fluid pressure required for driving the bucket, and activates the breaker for the excavation resistance exceeding the threshold value.

At this time, in the driving device for a bucket with a breaker according to the present invention, the breaker control means determines the magnitude of the excavation resistance from a maximum hydraulic pressure extracted from a plurality of hydraulic pressures required for driving the bucket. It is characterized in that the breaker is actuated for the excavation resistance exceeding the threshold value.

[0011]

According to the above construction, the breaker control means activates the breaker provided on the bucket only when the excavation resistance during the excavation operation exceeds a predetermined value, so that the excavation resistance depends on the hardness of the ground to be excavated. Automatically judge whether the breaker is used or not regardless of the operator's judgment. In particular, the breaker control means determines the magnitude of the digging resistance from the maximum hydraulic pressure extracted from the plurality of hydraulic pressures necessary for driving the bucket as a threshold value, and activates the breaker for the digging resistance exceeding the threshold value. The digging resistance exceeded the threshold value even if the bucket driving direction changed due to changes in bucket work such as scooping, cutting, and pulling work with the bucket, etc. Can be detected immediately and the breaker can be activated, thereby improving the work efficiency without interrupting the work.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a driving device for a bucket with a breaker according to the present invention; FIG. FIG. 1 is a side view showing an embodiment of a hydraulic shovel to which a drive device for a bucket with a breaker of the present invention is applied, and FIGS. 2 and 3 are a vertical sectional view and a plan view of a bucket portion of the hydraulic shovel shown in FIG. FIG. 4 is a circuit diagram showing one embodiment of the hydraulic circuit of the hydraulic shovel shown in FIG.

In a hydraulic excavator 11 shown in FIG. 1, a hydraulic breaker 13 for driving an excavating tooth 12 by hydraulic pressure has a bucket 1
4 is incorporated. As shown in FIG. 3, the excavated tooth 12 is composed of a main tooth 12a and sub tooth 12b arranged on both sides thereof. Since the sub tooth 12b is a fixed tooth, only the main tooth 12a is driven by the hydraulic breaker 13. As shown in FIGS. 2 and 3, the bucket 14 has a pin hole 15 for the connecting pin 7 connected to the tip of the arm 5 and a pin hole 16 for the connecting pin 9 connecting the tip of the rod 8 to the bracket 17. Has been drilled. A cutting edge 18a serving as a cutting blade is provided at a tip of a back plate 18 integrated with the bracket 17, and the above-mentioned sub tooth 12b is fixed to the vicinity of both side plates 19 of the cutting edge 18a. Left and right sub tooth 12
The main tooth 12a, which is located at the center of
In the space between 8 and the protective plate 20 covering the top central part thereof,
The bush 21 is inserted through the bush 21 so as to be able to move forward and backward, and is coupled via a chisel 22 to the breaker main body 13a incorporated in the space. The breaker body 13a is supplied with hydraulic oil supplied from a hydraulic circuit 23, which will be described later, provided outside the bucket 14 via a hose 24 via a switching valve 25, and drives the chisel 22 back and forth by hydraulic pressure.

The hydraulic breaker 13 includes a boom cylinder 4a.
The hydraulic oil is incorporated in the hydraulic circuit 23 shown in FIG. 4 together with the arm cylinder 5a or the bucket cylinder 6a, and hydraulic oil is supplied from a common oil tank 26 to the cylinders 4a, 5a, 6a via a pump 27. Each cylinder 4
Each of a, 5a, and 6a is configured to selectively supply and drive hydraulic oil to one of a head-side and a rod-side oil chambers, and is a three-position six-port switch for controlling supply and discharge of hydraulic oil. Valves 41, 51, 61 are provided for each of the cylinders 4a, 5a, 6a. FIG. 4 shows a 3-position 6-port switching valve 41,
51 and 61 are shown in a neutral state, and in this state, any hydraulic oil discharged from the pump 27
Of the cylinders 4a, 5a, and 6a are inactive. When the manual levers 41a, 51a, 61a are operated to switch the three-position six-port switching valves 41, 51, 61, for example, when the switching state in which the crossing line is illustrated in the display symbol in FIG. The cylinders 4a, 5a, 6a are supplied with hydraulic oil to a head-side oil chamber, and rods are sent out from the cylinders 4a, 5a, 6a. Conversely, when the switching state in which the parallel conduit is illustrated in the display symbol in FIG. 4 is selected, each cylinder 4a, 5a, 6a is supplied with hydraulic oil to the oil chamber on the rod side, The rod will be retracted.

The three-position six-port switching valves 41, 51,
Check valves 30 are respectively connected to the inlet portions of the input ports at the center of 61 to prevent high pressure from acting on the pump 27 under high load. In addition, a relief valve 32 is provided in a bypass pipe 31 connecting the oil tank 29 for receiving the recirculated hydraulic oil and the pump 27, and works to release the pressure to the oil tank 29 when an abnormally high pressure is generated. do.

The hose 24 communicating with the breaker body 13a contains two oil supply lines 33 and an oil discharge line 34, and the breaker body 13 is provided in the middle of the oil supply line 33.
a switching valve 25 for supplying or shutting off hydraulic oil to a
Is provided. The switching control of the switching valve 25 is automated, and in the embodiment, among the pressures of the respective hydraulic oils of the rod-side oil chamber of the boom cylinder 4a, the head-side oil chamber of the arm cylinder 5a, and the head-side oil chamber of the bucket cylinder 6a, The configuration is such that the highest hydraulic oil pressure is used for determining the threshold value for switching the switching valve 25. Specifically, first, a branch line 36a. Branched from a line leading to the rod-side oil chamber of the boom cylinder 4a and a line leading to the head-side oil chamber of the arm cylinder 5a. 36b is led to the input port of the shuttle valve 36 for selecting the high pressure input. Further, a line 37a connected to the output port of the shuttle valve 36
And a branch line 37b branched from a line leading to the head-side oil chamber of the bucket cylinder 6a, to another input port of the shuttle valve 37 for selecting a high-pressure input. And finally, a line 38 connected to the output port of the shuttle valve 37.
By connecting a to the sequence valve 38, the breaker control means is completed. The threshold value of the sequence valve 38 can be varied according to the spring force. When hydraulic oil having a pressure exceeding the threshold value is input, the input port and the output port communicate with each other, and the switching valve 25 Is switched to the breaker operating side.

Next, the operation of the driving device for a bucket with a breaker having the above configuration will be described.

First, when excavating hard ground, the load applied to the boom 4, the arm 5, or the bucket 14 varies. Therefore, when the pressure of the hydraulic oil supplied to the boom cylinder 4a, the arm cylinder 5a, or the bucket cylinder 6a fluctuates, the three cylinders 4a, 5a, 6a
The hydraulic oil having the highest pressure among the hydraulic oils supplied to the pump is selected by the shuttle valves 36 and 37 and the sequence valve 38 is provided.
Supplied to When the pressure of the hydraulic oil supplied to the sequence valve 38 exceeds a threshold pressure set in accordance with the spring force, the hydraulic oil supplied to the switching valve 25 via the sequence valve 38 causes the switching valve 25 to rotate. Is switched, and the working oil from the pump 27 is supplied to the breaker body 13a. The breaker body 13a to which the hydraulic oil has been supplied is moved to the main tooth 12a via the chisel 22 by the pressure of the hydraulic oil.
Is vibrated back and forth, and the hard ground can be crushed while driving the main tooth 12a vibrating at a low frequency into the ground having high excavation resistance.

On the other hand, for a ground of normal hardness,
Since the load applied to the boom 4, the arm 5, or the bucket 14 is within a normal range, the pressure of the hydraulic oil output from the shuttle valves 36 and 37 is less than the threshold pressure set for the sequence valve 38. . For this reason, the input port and the output port of the sequence valve 38 do not communicate with each other, so that no hydraulic oil is supplied to the switching valve 25, and no hydraulic oil is supplied to the breaker body 13a. Therefore,
The hydraulic breaker 13 remains stopped and the bucket 14
The original normal excavation is performed.

As described above, the above-mentioned hydraulic excavator 11
The hydraulic breaker 13 mounted on the bucket 14 can be automatically operated only when the excavation resistance exceeds a certain value and the hydraulic load fluctuates. Therefore, the hydraulic breaker 13 can be automatically operated according to the excavation work conditions. Unlike a conventional hydraulic excavator that operates the hydraulic breaker 13, the hydraulic breaker 13 can be operated or stopped according to the hardness of the ground that is actually excavated. Since it does not enter, the excavation work can always be performed by the optimal excavation method that matches the excavation conditions.

Since the magnitude of the excavation resistance of the ground to be excavated is determined based on the hydraulic pressure required to drive the bucket 14, the magnitude of the excavation resistance can be accurately determined.

In the above embodiment, the excavator 11 has a backhoe specification in which the bucket 14 is scraped rearward. It is preferable to connect the shuttle valves 36 and 37 to the pipeline leading to the oil chamber that generates a load pressure corresponding to the excavation resistance to be generated.

The driving device 39 for a bucket with a breaker described above is applicable to all construction machines using a bucket 14 in which a hydraulic breaker 13 is integrated, such as a wheel loader or a dozer shovel, in addition to the hydraulic excavator 11. It is.

[0024]

[Effects of the Invention] As described above, according to the present invention,
Automatically activates the breaker mounted on the bucket when the excavation resistance exceeds a certain value, and automatically activates or deactivates the breaker without the operator's judgment about the hardness of the ground actually being excavated Can be done.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a hydraulic shovel to which a driving device for a bucket with a breaker of the present invention is applied.

FIG. 2 is a longitudinal sectional view of a bucket portion of the excavator shown in FIG.

FIG. 3 is a plan view of a bucket portion of the excavator illustrated in FIG. 1;

FIG. 4 is a circuit diagram showing one embodiment of a hydraulic circuit of the hydraulic shovel shown in FIG.

FIG. 5 is a side view showing an example of a conventional hydraulic excavator.

[Explanation of symbols]

 Reference Signs List 4 boom 4a boom cylinder 5 arm 5a arm cylinder 6 bucket 6a bucket cylinder 11 hydraulic excavator 12 excavating tooth 13 hydraulic breaker 14 bucket 25 switching valve 36, 37 shuttle valve 38 sequence valve 39 drive device for bucket with breaker

Claims (1)

(57) [Scope of request for utility model registration] 1. A breaker for driving a digging tooth by fluid pressure, a bucket provided with the breaker, and a breaker control means for operating the breaker when digging resistance exceeds a predetermined value. In the drive device for a bucket with a breaker, the bucket is driven by a plurality of hydraulic cylinders, and the breaker control means determines the magnitude of the excavation resistance from a maximum hydraulic pressure extracted from a plurality of hydraulic pressures required for driving the bucket. A drive device for a bucket with a breaker, characterized in that a threshold value is determined and the breaker is actuated for excavation resistance exceeding the threshold value.